It is important to understand the polarization behavior of a high power laser field to predict system performance and correct factors hindering optimum behavior.
For example, laser beams have their polarizations distorted by the curvature of mirrors and the coatings on the mirrors. By analyzing the distortions of the polarizations in a laser beam the source of the distortion can to isolated and corrections made to improve beam quality.
In the past, polarization measurements have been made for the average polarization of the entire beam. This is useful information for some purposes but does not provide the detailed analysis of a beam necessary to study and improve the beam quality.